Rotary retort furnace



F. J, CONDIT ET AL ROTARY RETORT FURNAGE May 24, A193,2.

Filed April 8, 1930 N I m -A TTORNEY May 24, 1932- F. J. coNDlT ET AL. 41,859,381

ROTARYRETORT FURNACE Filed April 8, 1930 5 Sheets-Sheet 2 .May 24, 1932.F. .1. coNDlT ET AL ROTARY RETORT FURNACE` Filed April s, 1930 5sheetsheet 3 B a M dbf/A A'TTORNEY May 24, 1932. F. J. coNDlT ET AL1,859,381

ROTARY RETORT FURNAGE Filed April 8, 1950 5 Sheets-Sheet 4 finA Vfurnacefor termediate the ends thereof.

Patented May 24, 1932 Unirse srnras or MILWAUKEE, AND EDWIN L. SMALLEY,or wirrrnrrsir BAY,

ELECTRIC COMPANY, or MILWAUKEE, wisj HEVI DUTY CON SIN A CGEPORATIGN OFWSCONSIN PATENT einen ROTARYl RETORT FURNACE Application filed April 8,

Our invention relates broadly to rotary retort furnaces and moreparticularly to a con* struction of bearing support for a revolvingretort in a rotary retort furnace.

One of the objects of our invention is to provide a construction ofsupport for a rotatable retort in a rotary retort furnace; the retortmay be at an extremely slow rate whileV wherein the movement ofmaintained preventing the warpage or distortion of the retort undei theload.

Another object of our invention is to provide a construction of supportfor a rotary retort within the furnace intermediate the end bearing forthe retort for preventingdistortion of the retort under load conditions.

Still another object of provide a construction of intermediate port fora revolvable retort Where the supsupportinay be adjusted to reduce thetendency o" wai-page or distortion in the retort under the action of theload and to compensate for irregularities in the surface of theretort.

A further object of our invention "is to provide a construction port fora rotary retort in which a roller directly contacts with the exteriorsurface ofv the retort, with means for elevating or lowering the rollermember for properly adjusting the intermediate support lwith respect tothe rotary retort for relieving'the strain upon the retort intermediatethe loaded conditions.

A still further object of our invention is to provide a construction ofintermediate adjustable support arranged in a position between the endbearings of the retort and adjustable from the exterior of the retortproperly engaging the retort in- S'till another object of our inventionis to provide adjusting means for mounting' a rotating retort in whichreciprocating supportf ing means are actuated laterally with respect forpermit our invention isto of intermediate 'sup-- ends thereof underv1930. serial No. l12,591. u

vfollowing by in the specification hereinafter drawings in reference tothe accompanying which: Y

F "gure l is aside elevation partially broken away showing the interiorof the rotary retort and the arrangement ofthe adjustable i bearing inthe retort furnace inaccordance for the rotary retort illustrated inFigs. l

and 2.; Fig. 4L is an end elevation of the -iiitermediate support forthe rotary retort furnace illustrated in Figs. l and 2; Fig. 5 isy aAlongitudinal cross-sectional view takenV through the intermediatesupport; Fig. 6 is a plan view of the bed plate which supportstheadjustable bearing for properly centering the rotary retortl inaccordance with our invention ;f Fig; -7 is a cross-sectional viewthrough the bed plate shown in Fig. 6 on line 7 7 thereof ;"Fig;' 8` isa lateral cross-sectional View through Vthe'bed plate. illustrated inFig. 6 takenoii line 8"-@8 thereof; Fig. 9 is a plan view'ofthe levervwhich. is adjustably mounted with respect to 'the' bed plate 2 3; Fig/l0is a cross-sectionalview through the lever online 10-10 of Fig. 9; Fig.ll is a lat# eral cross-sectional ofv F ig.l 10`on'line'1l-,ll thereof;Fig. l2 is a cross-sectional view through the adjustable lever on line12-12 ofFig. 10'; Fig. 13 isa plan view of the yoke which carries theroller members and which engage the sides of the retort; Fig. 14 is aside elevation of the yoke illustratedin Fig. 13; and Fig. l5illustrates an arrangement; of'multiple adjustable means forcenteringthe rotary retort.

It hasheretofore been the practice con-j structing'furnaces ofthe retorttypeto have rolling supports located only beyond thev heads of thefurnace, thusV leaving a consid-l era-ble length of the retortunsupported. Such structures have view through the lever Y required thatthe retort 'y Vbe continuously revolved Auntil a visible'tem perature*disappeared inorder to prevent distortio'n of the retort bywarpage.This causes 3 be connected by any temperature up to 1650O a waste'ofltime and power used after the actual performance of work has ceased.Furthermore, it has been found in practice that furnaces constructed inaccordance with prior practice and having the retort filled or partiallyfilled, four was the lowest number of revolutions per hour withoutresulting distortion to the retort. Four revolutions er hour, as ageneral rule, would cause such a tumbling action of parts in the retortas to cause damage to any sharp edges of iinished parts, such as threadsof cap screws, bolts, set screws, etc.

In a rotary retort furnace the retort when loaded must be rotated atthat rate of speed which will prevent injury to the load under heatvtreatment within the retort and at the same time a suiiicientV rate ofspeed maintained which will avoid warping or distortion of the retortunder conditions of high temperature.`

Within the rotary retort furnace of our invention we. provideintermediate adjustable supports along the length of the retort forrelieving the strain upon the retort as it is rotated at hightemperature and enabling the retort to be revolved at a relatively slowrate of speed to avoid injury to theload within the retort. Y Heretoforewhen revolving a retort through a relatively large number of revolutionsper hour, the parts under' heat treatment tend to rub one with respectto another, and if this abrading or rubbing action becomes too great,damage to fine screw threads Vor sharp edged parts may result. In therotary retort furnace of our invention having adjustable meansintermediate ythe end bearings thereof for supporting the loaded retort,the rate at which the retort is revolved may be maintained very low andyet distortion and strain upon the walls of the retort substantiallyeliminated and injury ofthe parts abrading'eachV Y formed as part of anadjustable other practically prevented. Y

Referring to the drawings in detail, reference character 1 designates afurnace chamber surrounded Vby ceramic refractories 2 contained in theVfurnace shell .3, having end heads 4. Y Furnace chamber 1 may be heatedby any suitable means but is shown heated by electrical yelements 5.Reference character 6 designates a cylindrical retort having `outer endheads 7 to which is attached an inner headS. The inner and outer headssuitable means such as pipe 9 and tie rods 9a.k Pipe 9 affords Ya meansfor a gas connection when gas must beu sed for such purposes aspreventing oxidization or causing carburization of parts in the retort.`For the latter use it is sometimes found advisable to carryk the retortF.V to 17500 F., at which temperatures the non-oxidizing cast metal,such as nickel-chromium composition,

-. j loses considerable of itsstability as tol original idler 16constantly in character 10 indicates a form. Reference suitable clampingagainst the opposite end of retort 6. Reference character 11 indicates amotor driven train of gears enclosed in a suitable housing to impart arelatively low number of revolutions per minute to shaft 12 on which isa sprocket 13 connected to sprocket 14 or drum by means of sprocketchainlf15. Reference` character 16 denotes an idler sprocket on shaft 17having hub 18 and lever V19. Lever 19 has a helical coil 20 undertension to keep engagement with the slack side of chain 15. At 21 wehave shown a roller having trunnions 21a in a pivotal yoke 22 yandangularly movable on shaft 41 which is retained in position `byretaining pins 41a.

Yoke 22 has hub bearing 210 in close relationship to lugs 40, which arepart of lever 38 mounted at one end on a rounded knife-edge bearing 37which is supported as part of bed plate 23a.V The bed plate is alignedin one direction by means of depending flange 235 engaged in the brickwork of thel furnace and laterally by means of the ceramic refractorywalls as shown in Fig. 1. Lever 33 which is shown more-clearly in Figs.9, 10, 11 and 12, hastwo linger-like projections 38a one on each side oflever 33 to form an alignment means. On the opposite end of the lever 38there are two angularly disposed limiting flanges 39 to hold lever 33 onknifeedge 37. 39a is a rib centrally connecting flanges .39 and lodgedin a slot 37a in the knife edge 37 to prevent lateral dislodgement oflever 38.

In Fig. 3 reference a camv having trunnions 23 on the bed plate 23a.having an angularly projecting lever 33 eX- tending between the forks ofclevis 34 and mounted therein by means of pin 35, the pins beingretained by studs 35a. vThe clevis 34 is rod 36 adjustable byl nuts 36aengaging the bottom or external portion of furnace shell 3.

As will be understood from the drawings the yoke 22 with rollers 21 maybe elevated to near relationship to the outside of the retort. It willalsov be noted that if the radius of the retort opposite one roller` isgreater than the radius of the retort opposite the second roller, theyoke 22 having rollers 21, will revolve about pin 41 to compensate forthe difference in such radii or for irregularities on the outer surfaceof the retort.

While only one immediate support is shown in Fig. 1, we preferably usetwo intermediate supports character 42 shows 42a retained by lugs Camf42is shown as located equidistant from the longitudinal vertical centerline of the furnace, or we may use three or more supports.

The retort furnace is shown mounted on an underslung frame 24 supportedby stands 25, permitting the tilting of the retortY for loading anddischarging, On one stand25 there'VV the instance of the isa bracket 25asupporting a bearing for the shaft of hand wheel 30a. On such shaft 30is mounted a bevel pinion 29 engaging bevel gear'28 which'is attached toscrew 27 engaged in pivotally mounted nut 26. Movement of thread 27draws nut 26 to or away from hand wheel 30a. Nut'26 is supported bybracket 26a, which in turn is attached to a roller quadrant behind guardplates 256, the guard plates being advisable on account of the quadrantrolling on a rack of frame 25. Two flanges 32 on the retort spanning onewheel 3l keep the retort from sliding when the furnace is tilted.

Instead of the cam lifting device of Fig. 3 causing an upward or rollingmotion to yoke 22, a similar device might be us-ed to adjust a singleroller such as might be mounted directly on shaft 4l as shown in Fig.l5. In such instance two such lifting' devices are used in the assemblyshown in Fig. l5.

In the double lift arrangement we provide two lever members of identicalconstruction shown at 50 mounted upon two bed plates 23a. similar to thebed plate construction illustrated more particularly in Figs. 6, and 8.The bed plates are mounted on either side of a center line passingthrough the axis of the retort 6 and the adjust-ing rods 36 thereofextend through the furnace wall 2 and are vadjustable by means of nuts36a in amanner as has heretofore been described with respect to thesingle lift. The levers 50 differ from the construction of the lever 38,to the extent that lugs 52 project upwardly from levers 50 and providebearings for shaftmember 54@ which are pinned in position with respectthereto by means ,of 'pins 54o. A roller 54 is carried upon each shaftmember 54a and by virtue of the opposed relation of the two lifts, therollers 54 support the retort'from opposite sides vof the center linethereof. By adjusting the position of one or the other rod members 86either roller 54. may be brought into position to properly `@luide theretort in its rotary movement.

In order to observe the movement of the rotarv retort. we provide apeep-hole'in one end of the furnace through which the effect ofadjustments of the several lifts may be checked. Adjustments must bemade at the several points of support of the roller menibers withrespect to the rotary retort, and in double lift construction, made onboth of thelifts the operation of the readjustments must be to properlybalance tort. Y

Rotary retort furnaces embodying the principles of our invention havebeen found to be highly successful and practical. in operation. Inafurnace having a retort of la inches inside diameter and approximatelyl0 feet in length between the positions of the outer roller supportsrepresented at 31 in lin said furnace we have operated the would be lostby the requirement of keeping the retort revolving until an invisibletemperaturewas attained in the retort.

Furthermore, vclving the same described retort one or onehalfrevolutions per hour with the retort heated to 1700O F. and containingacharge of set screws being case hardened,no damage was causedto thelthreads of the screws. This brings the rotary retort furnace ina fieldfor which has not heretofore-been successfully accomplished by any otherfurnace of the retort type. The rotation of the retort is main; tainedat less than two revolutions per hour and yet strain and distortion uponthe retort are substantially jurious abrasion of prevented, while Ytheinf parts one with respect we have ascertained that re-r Y carburizingsharp edged parts,y

to another is avoided during the rotative vention are intended otherthan those im- A posed by the scope of the appended claims.

What we claim as new and desire to secure by Letters Patent of theUnited States is as follows:

l. In a rotary retort furnace, a furnace chamber, 'a rotaryretort, meanssupported by said furnace for journaling said rotary retort adjacentopposite ends thereof, and roller members mounted intermediate the endsof said retort and disposed wholly withchamber, said roller mem bersbeing vertically adjustable from the exterior of said furnacechamber forengaging said rotary retort'and supporting said retort when said retortis inoperative position.

2. In a furnace structure, a furnace chamber and a longitudinallyextending retort, means for journaling opposite endsv of said retort forrotaryv movement within said chamber, and a pluralityof means positionedwholly Within the furnace chamber andenlloo ics

the exterior walls of said retort for f ysupporting said retort forrotarymovement thereof under conditions of load, and means Y below saidchamber for adjusting said means with-respect to said retort.

@A support vfor a rotatable retort com- Y the exterior wall'of saidretort, a cam mountl ed 'upon VsaidV means and engageable with saidlever member, and means for angularly shifting said cam for moving saidlever member andY correspondingly adjusting the position of said rollerwith respect to said retort.

t. Supporting means for a rotatable retort comprising a supporting platemember, a fulcrum on said supporting plate member,

l a lever positioned upon said fulcrum, a roller all ' to said baseplate,

upwardly protruding member carri-el by said lever and engaging saidrotatable retort, and a cam journaled with respect to said supportingmeans, said cam being angularly shiftable for raising or lowering saidlever for correspondingly adjusting the position of said roller memberwith respect to said rotatable retort.

, LA,V support for a rotatable retort comprising a supporting plate, alev-er member fulcrumed with respect to said supporting plate, a rollermember carried by said lever member and engageable with the exteriorsurface lof said retort, a cam journaled with respect to said support ina position between the ends of said lever member remote from the fulcrumthereof, and means for angularly shifting the position of said lever member for correspondingly changing the position of said roller member withrespect to the exterior surface of said rotatable retort. 6. Supportingmeans for a rotary retort comprising a supporting plate having anportion adjacent one end thereof, a lever member having a pair ofdownwardly projecting portions adjacent one end thereof, the downwardlyprojecting portions of said lever member embracing the upwardlyprotruding portion of said plate for providing a fulcrum for said levermember, a cam journaled in said supporting means adjacent the undersurface of said lever member, means for angularly shifting said cam foradjustingftlie position of said lever member, and a roller journaledwith.

respect to said lever member, said roller engaging said rotary` retortfor supporting said retort in accordance with the corresponding angularmovement of said cam.

7. Supporting means for a rotatable retort comprising a base plate, alever fulcrumed with respect to said base plate, a cam beneath saidlever and journaled with respect means for adjusting the angularposition of Vsaid cam with respect to A said lever for shifting saidlever about the fulcruni thereof, and a roller by said lever, saidroller member engaging the exterior surface of a rotatable retort forsupporting said retort in accordance with the adjustment in position ofsaid cam.

8. Supporting means for a rotatable retort comprising a supportingplate, an upwardly Vprotruding member adjacent one end of said plate, a.lever fulcrumed adjacent one end thereof on said ber, a cam 'journaledwithjrespect to said ksupporting plate member carried upwardlyprotruding inem- Y ina position substantially vbeneath the opposite endof said lever, a yolre pivotally mounted upon said lever, and aplurality of roller members journaled in said yoke and rotatablyengaging said rotatable retort, said roller members being shiftable inposition in accordance with changes in the angular position of said cambeneath said lever. Y

9. ln a support for a rotatable retort, a supporting plate, an upwardlyprotruding member adjacent one end of saidsupporting plate, an angularlyshiftable cam journaled with respect to said supporting plate, a lever'member having a pair of downwardly extending angular portions adjacentone end thereof embracing the upwardly protruding portion of saidsupporting plate for providing a fulcrumy for said lever member, theopposite end of said lever member substantially embracing said angularlyshiftable cam, means for adjusting the angular relation of said cam withrespect to said lever member for raising or lowering said lever member,and a multiplicity of yroller members supported with respect to saidlever Vmember for engaging the exterior walls of a rotatable retort onoppositesides of the central axis` thereof.

l0. In a rotary retort furnace, a heat treatment chamber, a rotatableretort extending through said chamber and journaled adjacent oppositeends thereof, supporting means intermediate the j ournaled ends of saidretort comprising supporting plate members located beneath said retorton opposite sides of the central axis thereof, lever members fulcrumedadjacent the ends of said supporting means remote from the centralaxisof said retort and extending laterally to-ward the central axisthereof, a roller member carried by each of said leverpmembers andengageable with the exterior of said'retOrt, andy adjustablel camdevices located between said supporting. means and each of saidlevermembers substantially beneath said roller members for angula-rlyVshifting the position ,of said lever members on either side of thecentral axis of said retort for relieving the strain upon said retortintermediate the ends thereof under conditions of load and hightemperature. V

ln testimony whereof we affix our'signa-

